"Like all of you, I saw the anger. I understand it. I felt it. I have learned from it. And I know how much damage this has done to us as a party."

The tuition fees decision, which led to widespread vitriol towards the Liberal Democrats across the political spectrum was "by far the most painful part of our transition", Mr Clegg said.

The party leader argued that the new system, which see graduates pay the fees only once their income hits a certain level, was the best result which could be secured given Westminster's plan to raise contributions.

"The simple truth is that the Conservatives and Labour were both set on increasing fees, and in those circumstances we did the best thing we could," he told delegates.

"But we failed to properly explain those dilemmas. We failed to explain that there were no other easy options."

In a frank assessment of the party's declining poll ratings, Mr Clegg admitted being in government had not been "a walk in the park".

"I suspect none of us predicted just how tough it would turn out to be," he said.

"We’ve lost support, we’ve lost councillors and we lost a referendum. I know how painful it has been to face anger and frustration on the doorstep.

"Some of you may have even wondered: Will it all be worth it in the end? It will be."

But Mr Clegg argued that the Lib Dems had secured key policies on the NHS and human rights despite the relentless attacks on them by the media.

The Lib Dem leader also offered a resolute and non-negotiable commitment to preserving the Human Rights Act in the face of bitter opposition from Conservative backbenchers.